// Aseprite
// Copyright (C) 2018-2024  Igara Studio S.A.
// Copyright (C) 2001-2018  David Capello
//
// This program is distributed under the terms of
// the End-User License Agreement for Aseprite.

#ifndef APP_UI_EDITOR_H_INCLUDED
#define APP_UI_EDITOR_H_INCLUDED
#pragma once

#include "app/color.h"
#include "app/doc.h"
#include "app/doc_observer.h"
#include "app/pref/preferences.h"
#include "app/tools/active_tool_observer.h"
#include "app/tools/tool_loop_modifiers.h"
#include "app/ui/color_source.h"
#include "app/ui/editor/brush_preview.h"
#include "app/ui/editor/editor_hit.h"
#include "app/ui/editor/editor_observers.h"
#include "app/ui/editor/editor_state.h"
#include "app/ui/editor/editor_states_history.h"
#include "app/ui/tile_source.h"
#include "app/util/tiled_mode.h"
#include "doc/algorithm/flip_type.h"
#include "doc/frame.h"
#include "doc/image_buffer.h"
#include "doc/selected_objects.h"
#include "filters/tiled_mode.h"
#include "gfx/fwd.h"
#include "obs/connection.h"
#include "os/color_space.h"
#include "render/projection.h"
#include "render/zoom.h"
#include "ui/base.h"
#include "ui/cursor_type.h"
#include "ui/pointer_type.h"
#include "ui/timer.h"
#include "ui/widget.h"

#include <memory>
#include <set>

namespace doc {
class Layer;
class Sprite;
} // namespace doc
namespace gfx {
class Region;
}
namespace ui {
class Cursor;
class Graphics;
class View;
} // namespace ui

namespace app {
class Context;
class DocView;
class EditorCustomizationDelegate;
class EditorRender;
class PixelsMovement;
class Site;
class Transformation;

namespace tools {
class Ink;
class Pointer;
class Tool;
} // namespace tools

enum class AutoScroll {
  MouseDir,
  ScrollDir,
};

class Editor : public ui::Widget,
               public app::DocObserver,
               public IColorSource,
               public ITileSource,
               public tools::ActiveToolObserver {
public:
  enum EditorFlags {
    kNoneFlag = 0,
    kShowGrid = 1,
    kShowMask = 2,
    kShowOnionskin = 4,
    kShowOutside = 8,
    kShowDecorators = 16,
    kShowSymmetryLine = 32,
    kShowSlices = 64,
    kDefaultEditorFlags = (kShowGrid | kShowMask | kShowOnionskin | kShowOutside | kShowDecorators |
                           kShowSymmetryLine | kShowSlices)
  };

  enum class ZoomBehavior {
    CENTER, // Zoom from center (don't change center of the editor)
    MOUSE,  // Zoom from cursor
  };

  static ui::WidgetType Type();

  Editor(Doc* document, EditorFlags flags = kDefaultEditorFlags, EditorStatePtr state = nullptr);
  ~Editor();

  static Editor* activeEditor() { return m_activeEditor; }
  static void _setActiveEditor(Editor* editor) { m_activeEditor = editor; }
  static void destroyEditorSharedInternals();

  bool isActive() const { return (m_activeEditor == this); }
  bool isUsingNewRenderEngine() const;

  DocView* getDocView() { return m_docView; }
  void setDocView(DocView* docView) { m_docView = docView; }

  // Returns the current state.
  EditorStatePtr getState() { return m_state; }

  bool isMovingPixels() const;
  void dropMovingPixels();

  // Changes the state of the editor.
  void setState(const EditorStatePtr& newState);

  // Backs to previous state.
  void backToPreviousState();

  // Gets/sets the current decorator. The decorator is not owned by
  // the Editor, so it must be deleted by the caller.
  EditorDecorator* decorator() { return m_decorator; }
  void setDecorator(EditorDecorator* decorator) { m_decorator = decorator; }
  void getInvalidDecoratoredRegion(gfx::Region& region);

  EditorFlags editorFlags() const { return m_flags; }
  void setEditorFlags(EditorFlags flags) { m_flags = flags; }

  bool isExtraCelLocked() const { return m_flashing != Flashing::None; }

  Doc* document() { return m_document; }
  Sprite* sprite() { return m_sprite; }
  Layer* layer() { return m_layer; }
  frame_t frame() { return m_frame; }
  DocumentPreferences& docPref() { return m_docPref; }

  void getSite(Site* site) const;
  Site getSite() const;

  void setLayer(const Layer* layer);
  void setFrame(frame_t frame);

  const render::Projection& projection() const { return m_proj; }
  const render::Zoom& zoom() const { return m_proj.zoom(); }
  const gfx::Point& padding() const { return m_padding; }

  void setZoom(const render::Zoom& zoom);
  void setDefaultScroll();
  void setScrollToCenter();
  void setScrollAndZoomToFitScreen();
  void setEditorScroll(const gfx::Point& scroll);
  void setEditorZoom(const render::Zoom& zoom);

  // Updates the Editor's view.
  void updateEditor(const bool restoreScrollPos);

  // Draws the sprite taking care of the whole clipping region.
  void drawSpriteClipped(const gfx::Region& updateRegion);

  void flashCurrentLayer();

  // Convert ui::Display coordinates (pixel relative to the top-left
  // corner of the in the display content bounds) from/to
  // editor/sprite coordinates (pixel in the canvas).
  //
  // TODO we should rename these functions to displayToEditor() and editorToDisplay()
  gfx::Point screenToEditor(const gfx::Point& pt) const;
  gfx::Point screenToEditorCeiling(const gfx::Point& pt) const;
  gfx::PointF screenToEditorF(const gfx::Point& pt) const;
  gfx::Point editorToScreen(const gfx::Point& pt) const;
  gfx::PointF editorToScreenF(const gfx::PointF& pt) const;
  gfx::Rect screenToEditor(const gfx::Rect& rc) const;
  gfx::Rect editorToScreen(const gfx::Rect& rc) const;
  gfx::RectF editorToScreenF(const gfx::RectF& rc) const;

  void add_observer(EditorObserver* observer);
  void remove_observer(EditorObserver* observer);

  void setCustomizationDelegate(EditorCustomizationDelegate* delegate);

  EditorCustomizationDelegate* getCustomizationDelegate() { return m_customizationDelegate; }

  // Returns the visible area of the viewport in sprite coordinates.
  gfx::Rect getViewportBounds();

  // Returns the visible area of the active sprite.
  gfx::Rect getVisibleSpriteBounds();

  gfx::Size canvasSize() const;
  gfx::Point mainTilePosition() const;
  void expandRegionByTiledMode(gfx::Region& rgn, const bool withProj) const;
  void collapseRegionByTiledMode(gfx::Region& rgn) const;

  // Changes the scroll to see the given point as the center of the editor.
  void centerInSpritePoint(const gfx::PointF& spritePos);
  void centerInSpritePoint(const gfx::Point& spritePos);
  gfx::PointF spritePointInCenter() const;

  void updateStatusBar();

  // Control scroll when cursor goes out of the editor viewport.
  gfx::Point autoScroll(const ui::MouseMessage* msg, const AutoScroll dir);

  tools::Tool* getCurrentEditorTool() const;
  tools::Ink* getCurrentEditorInk() const;

  tools::ToolLoopModifiers getToolLoopModifiers() const { return m_toolLoopModifiers; }
  bool isAutoSelectLayer();

  // Returns true if we are able to draw in the current doc/sprite/layer/cel.
  bool canDraw();

  // Returns true if the cursor is inside the active mask/selection.
  bool isInsideSelection();

  // Returns true if the cursor is inside the selection and the
  // selection mode is the default one which prioritizes and easy
  // way to move the selection.
  bool canStartMovingSelectionPixels();

  // Returns true if the range selected in the timeline should be
  // kept. E.g. When we are moving/transforming pixels on multiple
  // cels, the MovingPixelsState can handle previous/next frame
  // commands, so it's nice to keep the timeline range intact while
  // we are in the MovingPixelsState.
  bool keepTimelineRange();

  // Returns the element that will be modified if the mouse is used
  // in the given position.
  EditorHit calcHit(const gfx::Point& mouseScreenPos);

  void setZoomAndCenterInMouse(const render::Zoom& zoom,
                               const gfx::Point& mousePos,
                               ZoomBehavior zoomBehavior);

  void pasteImage(const Image* image,
                  const Mask* mask = nullptr,
                  const gfx::Point* position = nullptr);

  void startSelectionTransformation(const gfx::Point& move, double angle);
  void startFlipTransformation(doc::algorithm::FlipType flipType);
  void updateTransformation(const Transformation& transform);

  // Used by EditorView to notify changes in the view's scroll
  // position.
  void notifyScrollChanged();
  void notifyZoomChanged();

  // Returns true and changes to ScrollingState when "msg" says "the
  // user wants to scroll". Same for zoom.
  bool checkForScroll(ui::MouseMessage* msg);
  bool checkForZoom(ui::MouseMessage* msg);

  // Start Scrolling/ZoomingState
  void startScrollingState(ui::MouseMessage* msg);
  void startZoomingState(ui::MouseMessage* msg);

  // Animation control
  void play(const bool playOnce, const bool playAll, const bool playSubtags);
  void stop();
  bool isPlaying() const;

  // Shows a popup menu to change the editor animation speed.
  void showAnimationSpeedMultiplierPopup();
  double getAnimationSpeedMultiplier() const;
  void setAnimationSpeedMultiplier(double speed);

  // Functions to be used in EditorState::onSetCursor()
  void showMouseCursor(ui::CursorType cursorType, const ui::Cursor* cursor = nullptr);
  void showBrushPreview(const gfx::Point& pos);

  // Gets the brush preview controller.
  BrushPreview& brushPreview() { return m_brushPreview; }

  static EditorRender& renderEngine() { return *m_renderEngine; }

  // IColorSource
  app::Color getColorByPosition(const gfx::Point& pos) override;

  // ITileSource
  doc::tile_t getTileByPosition(const gfx::Point& pos) override;

  void setTagFocusBand(int value) { m_tagFocusBand = value; }
  int tagFocusBand() const { return m_tagFocusBand; }

  // Returns true if the Shift key to draw straight lines with a
  // freehand tool is pressed.
  bool startStraightLineWithFreehandTool(const tools::Pointer* pointer);

  // Functions to handle the set of selected slices.
  bool isSliceSelected(const doc::Slice* slice) const;
  void clearSlicesSelection();
  void selectSlice(const doc::Slice* slice);
  bool selectSliceBox(const gfx::Rect& box);
  void selectAllSlices();
  bool hasSelectedSlices() const { return !m_selectedSlices.empty(); }
  void slicesTransforms(bool value) { m_slicesTransforms = value; }
  bool slicesTransforms() const { return m_slicesTransforms; }

  // Called by DocView's InputChainElement::onCancel() impl when Esc
  // key is pressed to cancel the active selection.
  void cancelSelections();

  // Properties to show information in the status bar
  bool showAutoCelGuides() const { return m_showAutoCelGuides; }

  // Used in case an unhandled exception was caught when processing
  // an Editor or EditorState event.
  void showUnhandledException(const std::exception& ex, const ui::Message* msg);

  static void registerCommands();

protected:
  bool onProcessMessage(ui::Message* msg) override;
  void onSizeHint(ui::SizeHintEvent& ev) override;
  void onResize(ui::ResizeEvent& ev) override;
  void onPaint(ui::PaintEvent& ev) override;
  void onInvalidateRegion(const gfx::Region& region) override;
  void onSamplingChange();
  void onFgColorChange();
  void onContextBarBrushChange();
  void onTiledModeBeforeChange();
  void onTiledModeChange();
  void onShowExtrasChange();

  // DocObserver impl
  void onColorSpaceChanged(DocEvent& ev) override;
  void onExposeSpritePixels(DocEvent& ev) override;
  void onSpritePixelRatioChanged(DocEvent& ev) override;
  void onBeforeRemoveLayer(DocEvent& ev) override;
  void onBeforeRemoveCel(DocEvent& ev) override;
  void onAddTag(DocEvent& ev) override;
  void onRemoveTag(DocEvent& ev) override;
  void onRemoveSlice(DocEvent& ev) override;
  void onBeforeLayerVisibilityChange(DocEvent& ev, bool newState) override;
  void onBeforeLayerEditableChange(DocEvent& ev, bool newState) override;

  // ActiveToolObserver impl
  void onActiveToolChange(tools::Tool* tool) override;

private:
  enum class Flashing { None, WithFlashExtraCel, WaitingDeferedPaint };

  void setStateInternal(const EditorStatePtr& newState);
  void updateQuicktool();
  void updateToolByTipProximity(ui::PointerType pointerType);

  // firstFromMouseDown=true when we call this function from the
  // first MouseDown message (instead of KeyDown).
  void updateToolLoopModifiersIndicators(const bool firstFromMouseDown = false);

  void drawBackground(ui::Graphics* g);
  void drawSpriteUnclippedRect(ui::Graphics* g, const gfx::Rect& rc);
  void drawMaskSafe();
  void drawMask(ui::Graphics* g);
  void drawGrid(ui::Graphics* g,
                const gfx::Rect& spriteBounds,
                const gfx::Rect& gridBounds,
                const app::Color& color,
                int alpha);
  void drawSlices(ui::Graphics* g);
  void drawTileNumbers(ui::Graphics* g, const Cel* cel);
  void drawCelBounds(ui::Graphics* g, const Cel* cel, const gfx::Color color);
  void drawCelGuides(ui::Graphics* g, const Cel* cel, const Cel* mouseCel);
  void drawCelHGuide(ui::Graphics* g,
                     const int sprX1,
                     const int sprX2,
                     const int scrX1,
                     const int scrX2,
                     const int scrY,
                     const gfx::Rect& scrCelBounds,
                     const gfx::Rect& scrCmpBounds,
                     const int dottedX);
  void drawCelVGuide(ui::Graphics* g,
                     const int sprY1,
                     const int sprY2,
                     const int scrY1,
                     const int scrY2,
                     const int scrX,
                     const gfx::Rect& scrCelBounds,
                     const gfx::Rect& scrCmpBounds,
                     const int dottedY);
  gfx::Rect getCelScreenBounds(const Cel* cel);

  void setCursor(const gfx::Point& mouseDisplayPos);

  // Draws the specified portion of sprite in the editor.  Warning:
  // You should setup the clip of the screen before calling this
  // routine.
  void drawOneSpriteUnclippedRect(ui::Graphics* g, const gfx::Rect& rc, int dx, int dy);

  gfx::Point calcExtraPadding(const render::Projection& proj);

  void invalidateCanvas();
  void invalidateIfActive();
  void updateAutoCelGuides(ui::Message* msg);

  int otherLayersOpacity() const;

  // Stack of states. The top element in the stack is the current state (m_state).
  EditorStatesHistory m_statesHistory;
  EditorStatesHistory m_deletedStates;

  // Current editor state (it can be shared between several editors to
  // the same document). This member cannot be NULL.
  EditorStatePtr m_state;

  // Current decorator (to draw extra UI elements).
  EditorDecorator* m_decorator;

  Doc* m_document;           // Active document in the editor
  Sprite* m_sprite;          // Active sprite in the editor
  Layer* m_layer;            // Active layer in the editor
  frame_t m_frame;           // Active frame in the editor
  render::Projection m_proj; // Zoom/pixel ratio in the editor
  DocumentPreferences& m_docPref;
  // Helper functions affected by the current Tiled Mode.
  app::TiledModeHelper m_tiledModeHelper;

  // Brush preview
  BrushPreview m_brushPreview;

  tools::ToolLoopModifiers m_toolLoopModifiers;

  // Extra space around the sprite.
  gfx::Point m_padding;

  // Marching ants stuff
  ui::Timer m_antsTimer;
  int m_antsOffset;

  obs::scoped_connection m_samplingChangeConn;
  obs::scoped_connection m_fgColorChangeConn;
  obs::scoped_connection m_contextBarBrushChangeConn;
  obs::scoped_connection m_showExtrasConn;

  // Slots listening document preferences.
  obs::scoped_connection m_tiledConnBefore;
  obs::scoped_connection m_tiledConn;
  obs::scoped_connection m_gridConn;
  obs::scoped_connection m_pixelGridConn;
  obs::scoped_connection m_bgConn;
  obs::scoped_connection m_onionskinConn;
  obs::scoped_connection m_symmetryModeConn;

  EditorObservers m_observers;

  EditorCustomizationDelegate* m_customizationDelegate;

  DocView* m_docView;

  // Last known mouse position received by this editor when the
  // mouse button was pressed. Used for auto-scrolling. To get the
  // current mouse position on the editor you can use
  // ui::Display::lastMousePos().
  gfx::Point m_oldPos;

  EditorFlags m_flags;

  bool m_secondaryButton;
  Flashing m_flashing;

  // Animation speed multiplier.
  double m_aniSpeed;
  bool m_isPlaying;

  // The Cel that is above the mouse if the Ctrl (or Cmd) key is
  // pressed (move key).
  Cel* m_showGuidesThisCel;
  bool m_showAutoCelGuides;

  // Focused tag band. Used by the Timeline to save/restore the
  // focused tag band for each sprite/editor.
  int m_tagFocusBand;

  // Used to restore scroll when the tiled mode is changed.
  // TODO could we avoid one extra field just to do this?
  gfx::Point m_oldMainTilePos;

#if ENABLE_DEVMODE
  gfx::Rect m_perfInfoBounds;
#endif

  // For slices
  doc::SelectedObjects m_selectedSlices;
  // When true, modifications to slices positions/sizes will transform the
  // pixels inside their boundaries.
  bool m_slicesTransforms = false;

  // Active sprite editor with the keyboard focus.
  static Editor* m_activeEditor;

  // The render engine must be shared between all editors so when a
  // DrawingState is being used in one editor, other editors for the
  // same document can show the same preview image/stroke being drawn
  // (search for Render::setPreviewImage()).
  static std::unique_ptr<EditorRender> m_renderEngine;
};

} // namespace app

#endif
